So, Xenon is a noble gas, and doesn't decay once produced. Why is this important? All the planets in our solar system have the same Xe-129 to Xe-130 ratio, EXCEPT for Mars and Earth. Earth is explainable, because we used to have the same ratio as the other planets before nuclear bombs were created. Mars HAS 271% THE AMOUNT OF XE-129 COMPARED TO PRE-NUCLEAR EARTH. The only explanation for that much Xe-129 is nuclear bombings, and that's what caused Mars to be the wasteland it is today. NASA has had this evidence since 1976 when Viking-1 measured Xe isotopes.

this is the only conspiracy theory i'll ever believe

Also, any asteroid that could've possibly caused this in-balance of Xe-129 and Xe-130 would've needed to have a 1000km diameter, but that would've caused a huge crater, which is nowhere to be found.

mars is theorized to have had water across is surface and theres alot of evidence supporting it, if so it means that when it impacted it wouldnt have made that large of a crater and if it did it would have been broken down over time